Semiconductor device with improved aspect ratio

Abstract

A semiconductor device includes a first stacked body and a second stacked body stacked on each other. A columnar semiconductor film penetrates the first stacked body and the second stacked body, and a charge storage film is between the first semiconductor film and the stacked bodies. A first dummy memory cell is at a position where a first conductive layer in the first stacked body that is closest to the second stacked body intersects the columnar semiconductor film and the charge storage film. A memory cell is at a position where another conductive layer of the first stacked body intersects the columnar semiconductor film. The distance between an upper corner of the first conductive layer and the charge storage film is greater than the distance between an upper corner of the second conductive layer and the charge storage film.

What is claimed is: 
     
       1. A semiconductor device, comprising:
 a first stacked body including a plurality of conductive layers stacked with insulating layers therebetween; 
 a second stacked body including a plurality of conductive layers stacked with insulating layers therebetween, the second stacked body being above the first stacked body; 
 a first semiconductor film that has a columnar shape and penetrates the first stacked body and the second stacked body in a stacking direction; and 
 a first charge storage film between the first semiconductor film and the first stacked body and between the first semiconductor film and the second stacked body, wherein 
 a first dummy memory cell is at a position where a first conductive layer among the plurality of conductive layers in the first stacked body that is closest to the second stacked body intersects the first semiconductor film and the first charge storage film, 
 a first memory cell is at a position where a second conductive layer among the plurality of conductive layers in the first stacked body that is farther from the second stacked body than the first conductive layer intersects the first semiconductor film and the first charge storage film, and 
 a distance between an end portion of an upper surface of the first conductive layer and the first charge storage film in a plane direction orthogonal to the stacking direction is greater than a distance between an end portion of an upper surface of the second conductive layer and the first charge storage film in the plane direction. 
 
     
     
       2. The semiconductor device according to  claim 1 , wherein
 a second dummy memory cell is at a position where a third conductive layer among the plurality of conductive layers in the second stacked body that is closest to the first stacked body intersects the first semiconductor film and the first charge storage film, and 
 the distance between the end portion of the upper surface of the first conductive layer and the first charge storage film in the plane direction is greater than a distance between an end portion of an upper surface of the third conductive layer and the first charge storage film in the plane direction. 
 
     
     
       3. The semiconductor device according to  claim 2 , wherein an interval between the first conductive layer and the third conductive layer in the stacking direction is greater than an interval between the first conductive layer and the second conductive layer in the stacking direction. 
     
     
       4. The semiconductor device according to  claim 1 , wherein
 a second memory cell is at a position where a fourth conductive layer among the plurality of conductive layers in the first stacked body that is farther from the second stacked body than the second conductive layer intersects the first semiconductor film and the first charge storage film, and 
 the distance between the end portion of the upper surface of the second conductive layer and the first charge storage film in the plane direction is greater than a distance between an end portion of an upper surface of the fourth conductive layer and the first charge storage film in the plane direction. 
 
     
     
       5. The semiconductor device according to  claim 1 , further comprising:
 a first insulating film between the first charge storage film and the first conductive layer; and 
 a second insulating film between the first insulating film and the first conductive layer, the second insulating film having a composition different from that of the first insulating film. 
 
     
     
       6. The semiconductor device according to  claim 5 , further comprising:
 a third insulating film between the first insulating film and the second conductive film, the third insulating film having a composition different from those of both the first insulating film and the second insulating film. 
 
     
     
       7. The semiconductor device according to  claim 6 , wherein a dielectric constant of the third insulating film is lower than a dielectric constant of the first insulating film. 
     
     
       8. The semiconductor device according to  claim 1 , wherein a central end portion of the second conductive layer in the stacking direction is recessed more than at least one of the end portion of the upper surface or an end portion of a lower surface of the second conductive layer with respect to a center of the first semiconductor film. 
     
     
       9. The semiconductor device according to  claim 1 , wherein a central end portion of the first conductive layer in the stacking direction protrudes beyond at least one of the end portion of the upper surface or an end portion of a lower surface of the first conductive layer with respect to a side of a center of the first semiconductor film. 
     
     
       10. The semiconductor device according to  claim 1 , wherein the first semiconductor film is curved toward the first conductive layer at a position intersecting with the first conductive layer. 
     
     
       11. The semiconductor device according to  claim 1 , wherein a channel length of the first dummy memory cell at the position where the first conductive layer intersects the first semiconductor film, and the first charge storage film is longer than a channel length of the first memory cell at the position where the second conductive layer intersects the first semiconductor film and the first charge storage film. 
     
     
       12. A semiconductor device, comprising:
 a first stacked body including a plurality of conductive layers stacked with insulating layers therebetween; 
 a second stacked body including a plurality of conductive layers stacked with insulating layers therebetween, the second stacked body being above the first stacked body; 
 a first semiconductor film that has a columnar shape and penetrates the first stacked body and the second stacked body in a stacking direction; and 
 a first charge storage film between the first semiconductor film and the first stacked body and between the first semiconductor film and the second stacked body, wherein 
 the first stacked body includes a first conductive layer, which is an uppermost conductive layer of the plurality of conductive layers in the first stacked body, and a second conductive layer of the plurality of conductive layers in the first stacked body that is adjacent to the first conductive layer, 
 the second stacked body includes a third conductive layer, which is a lowermost conductive layer of the plurality conductive layers in the second stacked body, 
 a spacing interval between the first conductive layer and the third conductive layer in the stacking direction is greater than a spacing interval between the first conductive layer and the second conductive layer in the stacking direction, 
 a curvature of the third conductive layer on a peripheral surface facing the first semiconductor film is greater than a curvature of the first conductive layer on a peripheral surface facing the first semiconductor film, and 
 a distance between an end portion of an upper surface of the first conductive layer and the first charge storage film in a plane direction orthogonal to the stacking direction is greater than a distance between an end portion of an upper surface of the second conductive layer and the first charge storage film in the plane direction, and also greater than a distance between an end portion of an upper surface of the third conductive layer and the first charge storage film in the plane direction. 
 
     
     
       13. The semiconductor device according to  claim 12 , wherein
 the first stacked body further includes a fourth conductive layer of the plurality of conductive layers in the first stacked body that is adjacent to the second conductive layer, and 
 the distance between the end portion of the upper surface of the second conductive layer and the first charge storage film in the plane direction is greater than a distance between an end portion of an upper surface of the fourth conductive layer and the first charge storage film in the plane direction. 
 
     
     
       14. The semiconductor device according to  claim 12 , further comprising:
 a first insulating film between the first charge storage film and the first conductive layer; and 
 a second insulating film between the first insulating film and the first conductive layer, the second insulating film having a composition different from that of the first insulating film. 
 
     
     
       15. The semiconductor device according to  claim 14 , further comprising:
 a third insulating film between the first insulating film and the second conductive film, the third insulating film having a composition different from those of the first insulating film and the second insulating film. 
 
     
     
       16. The semiconductor device according to  claim 15 , wherein a dielectric constant of the third insulating film is lower than a dielectric constant of the first insulating film. 
     
     
       17. The semiconductor device according to  claim 12 , wherein a central end portion of the second conductive layer in the stacking direction is recessed more than at least one of the end portion of the upper surface or an end portion of a lower surface of the second conductive layer with respect to a center of the first semiconductor film. 
     
     
       18. The semiconductor device according to  claim 12 , wherein a central end portion of the first conductive layer in the stacking direction protrudes beyond at least one of the end portion of the upper surface or an end portion of a lower surface of the first conductive layer with respect to a side of a center of the first semiconductor film. 
     
     
       19. The semiconductor device according to  claim 12 , wherein the first semiconductor film is curved toward the first conductive layer at a position intersecting with the first conductive layer. 
     
     
       20. The semiconductor device according to  claim 12 , wherein a channel length of a first transistor formed at a position where the first conductive layer intersects the first semiconductor film, and the first charge storage film is longer than a channel length of a second transistor formed at a position where the second conductive layer intersects the first semiconductor film and the first charge storage film.